Method of reducing a level of metallic species contamination of a fluid

ABSTRACT

Sorption media for removal of contaminants from fluid streams are provided. The sorption media comprise an active compound bound or linked to a support substrate or matrix. Support substrates can include iron- and alumina-based materials. A method for making sorption media for the removal of contaminants from fluid streams is also described. The method includes selecting a support substrate, and, optionally, providing a doping mixture comprising an active compound. The selected support substrate can be contacted with the doping mixture to form a doped mixture. The doped mixture can be reacted at a predetermined temperature and atmospheric environment for a predetermined duration to form an active media, wherein the active compound is bound or linked to the support substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.12/830,684 filed on Jul. 6, 2010, entitled Media for Removal ofContaminants from Fluid Streams and Method of Making and Using Same,which claims the benefit of U.S. Provisional Patent Application Ser. No.61/223,149 filed on Jul. 6, 2009, entitled Media for Removal ofContaminants from Fluid Streams and Method of Making and Using Same andU.S. Provisional Patent Application Ser. No. 61/310,773 filed on Mar. 5,2010, entitled Media for Removal of Contaminants from Fluid Streams andMethod of Making and Using Same, all of which are incorporated byreference herein.

This application is related to the following U.S. patents:

-   -   U.S. Pat. No. 7,341,667, entitled Process For Reduction Of        Inorganic Contaminants From Waste Streams, filed Oct. 29, 2004,        and issued Mar. 11, 2008,    -   U.S. Pat. No. 7,479,230, entitled Process For Reduction Of        Inorganic Contaminants From Waste Streams, filed Feb. 1, 2008,        and issued Jan. 20, 2009, and    -   U.S. Pat. No. 7,449,118, entitled Process For Reduction Of        Inorganic Contaminants From Waste Streams, filed Feb. 1, 2008,        and issued Nov. 11, 2008,        the contents of each of which is incorporated by reference        herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to the use of chemical sorbentsto reduce the levels of contaminants in waste streams.

2. Description of Related Art

Industrial pollutants such as heavy metals, D-block metals, mercury andarsenic pose significant health-related risks to the public. Forexample, several metal ions and transition metal ions have beenassociated with asthma symptoms such as activation of mast cells andenhanced allergen-mediated mast cell activation. Walczak-Crzewiecka, etal. “Environmentally Relevant Metal and Transition Metal Ions Enhance FcRI-Mediated Mast Cell Activation,” Env. Health Perspectives 111(5) (May2003). Because these substances are generated as a by-product ofindustrial processes, it is important to find effective means to reducetheir release into the environment.

For example, mercury emissions from coal-fired utilities, commercialboilers and solid waste incinerators represent a serious environmentalproblem and have been the focus of many regulatory deliberations. Atpresent, coal-fired power plants emit the largest source of mercuryemissions at 32.7%. Municipal waste incinerators and non-utility boilerseach contribute approximately 18% of mercury emissions. Medical wasteincinerators contribute 10% of gas phase mercury emissions. In additionto gas phase mercury contamination, mercury contaminant exists in waterphase as well such as water waste discharged by petroleum refineries andsteel mills. For example, water phase contaminants may includeelemental, ionic, organometallic, and/or inorganic mercury species.

Mercury exposure has been associated with neurological and developmentaldamage in humans. Developing fetuses and young children are atparticular risk of the harmful effects of mercury exposure. Mercurycontamination is also a concern for populations exposed to dentalpractices or dental waste, clinical chemistry laboratories, pathologylaboratories, research laboratories, chlor-alkali facilities, and healthcare waste incinerators. However, despite the desire to reduce mercuryemissions, presently there are no commercially available technologies tocontrol mercury emissions.

Similarly, exposure to arsenic poses potentially significant healthrisks. Arsenic is a natural element, distributed throughout the soil andin many kinds of rock. Because of its ubiquitous presence, arsenic isfound in minerals and ores that contain metals used for industrialprocesses. When these metals are mined or heated in smelters, thearsenic is released into the environment as a fine dust. Arsenic mayalso enter the environment from coal-fired power plants and incineratorsbecause coal and waste products contain some arsenic. Once arsenicenters the environment, it cannot be destroyed.

Arsenic exposure causes gastrointestinal problems, such as stomach ache,nausea, vomiting, and diarrhea. Arsenic exposure can also yielddecreased production of red and white blood cells, skin changes that mayresult in skin cancer, and irritated lungs. Inorganic arsenic has beenlinked to several types of cancer and is classified as a Group A, humancarcinogen. In high amounts (above about 60,000 ppb in food or water),arsenic may be fatal. Similar adverse effects have been associated withother inorganic contaminants such as cadmium, chromium, lead, andselenium.

Various carbon-based sorbents have been identified for removing mercuryvapor from gas streams. T. R. Carey and C. F. Richardson, “AssessingSorbent Injection Mercury Control Effectiveness in Flue Gas Streams,”Environmental Progress 19(3):167-174 (Fall 2000). For example,Selexsorb® HG (Alcoa World Alumina, LLC, Pittsburgh, Pa.) and Mersorb®(Nucon International, Inc., Columbus, OH) are commercially availablecarbon-based mercury sorbents. Recycled tires have also been identifiedas a source of activated carbon that could be used for mercury removal.C. Lehmann et al., “Recycling Waste Tires for Air-Quality Control,”January 2000. Activated carbon has many drawbacks for use in large-scaleindustrial processes, however. In particular, commercially availableactivated carbon is a relatively expensive sorbent. Althoughtransformation of waste tires into activated carbon is anenvironmentally friendly means of recycling harmful waste, it is acomplicated, lengthy, energy-intensive and time-consuming process.Additionally, the yield of activated carbon from waste tires isrelatively low.

Currently, carbon-based sorbents can be used for removal of contaminantsfrom water, primarily through an adsorption effect of the carbon.However, this method suffers from drawbacks such as washing off of theactive materials, thus making the use of carbon-based sorbentineffective. In addition, the used active carbon materials need to bedisposed of as a hazardous material, therefore adding cost andcontributing to further environmental problems.

Other currently used methods include the use of catalysts to removemercury from hydrocarbon gases. Similarly, such methods are noteffective in aqueous streams due to washing off of the active catalysts.

Thus, there is a need for new technologies to efficiently andcost-effectively reduce the level of inorganic contaminants, such asmercury and arsenic for example, in industrial emissions andspecifically in aqueous streams.

BRIEF SUMMARY OF THE INVENTION

A sorption media for removal or reduction of contaminants from a fluidstream is described, comprising an active compound linked to or bound toa support substrate or matrix. A method of making a sorption media isalso described.

In one aspect of the invention, a sorption media includes a supportsubstrate and a sulfur species chemically bonded to the supportsubstrate. The support substrate comprises a porous metallic material.The media includes at least 10 mol % aluminum species. Optionally, thesulfur species is chemically bonded to the support substrate by at leastone of an ionic bond and a covalent bond.

In another aspect of the invention, the sorption media has a contaminantcapacity of at least one of at least 1000 mg-mercury/kg-media, at least2000 mg-mercury/kg-media, at least 3000 mg-mercury/kg-media, and atleast 10,000 mg-mercury/kg-media.

In a further aspect of the invention, sorption media includes a supportsubstrate and a sulfur species chemically bonded to the supportsubstrate. The support substrate comprises a porous metallic material.The media includes at least 9 mol % iron species. Optionally, the sulfurspecies is chemically bonded to the support substrate by at least one ofan ionic bond and a covalent bond.

In yet another aspect of the invention, the sorption media has acontaminant capacity of at least one of at least 400mg-mercury/kg-media, at least 1000 mg-mercury/kg-media, at least 3500mg-mercury/kg-media, and at least 12,000 mg-mercury/kg-media.

In still a further aspect of the invention, a method of manufacturing asorption media includes selecting a support substrate comprising aporous metallic material, providing a doping mixture comprising a firstsulfur species dissolved in a solvent, and contacting the selectedsupport substrate with the doping mixture at a first temperature for afirst duration to form a doped substrate. The method also includesreacting the doped substrate at a second temperature in a selectedatmospheric environment for a second duration to form the sorptionmedia. The sorption media comprises a second sulfur species chemicallybonded to the support substrate. Optionally, the second sulfur speciesis chemically bonded to the support substrate by at least one of anionic bond and a covalent bond.

In one aspect of the invention, a method of manufacturing a sorptionmedia includes selecting a support substrate comprising a porousmetallic material, selecting an atmospheric environment comprising atleast hydrogen sulfide, and reacting the support substrate at a firsttemperature in the selected atmospheric environment for a first durationto form the sorption media. The selected sorption media comprises asulfur species chemically bonded to the support substrate. Optionally,the second sulfur species is chemically bonded to the support substrateby at least one of an ionic bond and a covalent bond.

In a further aspect of the invention, the method also includes mixingelemental sulfur with the selected substrate before reacting the supportsubstrate in the selected atmospheric environment.

In another aspect of the invention, a method of reducing a level ofmetallic species contamination of a fluid includes contacting the fluidincluding the metallic species contamination with a sorption media. Thesorption media including a sulfur species chemically bonded to a supportsubstrate. Optionally, the sulfur species is chemically bonded to thesupport substrate by at least one of an ionic bond and a covalent bond.

In still a further aspect of the invention, the metallic speciescontamination comprises at least one ionic mercury species. The methodalso includes selecting the sorption media for contacting the fluid froma plurality of sorption medias based on the sulfur species of theselected sorption media including a sulfide species.

In yet another aspect of the invention, the metallic speciescontamination comprises at least one inorganic mercury species. Themethod also includes selecting the sorption media for contacting thefluid from a plurality of sorption medias based on the sulfur species ofthe selected sorption media including a sulfate species.

In another aspect of the invention, the metallic species contaminationcomprises at least one inorganic mercury species and at least one ionicmercury species, the method further comprising selecting the sorptionmedia for contacting the fluid from a plurality of sorption medias basedon the sulfur species of the selected sorption media including a sulfatespecies and a sulfide species.

In an aspect of the invention, the metallic species contaminationcomprises at least one inorganic mercury species and at least one ionicmercury species. The method also includes selecting at least a first anda second sorption media for contacting the fluid from a plurality ofsorption medias based on the sulfur species of the first selectedsorption media including a sulfate species and the sulfur species on thesecond selected media including a sulfide species.

As used herein, the terms “support substrate” and “matrix” are usedinterchangeably. As used herein, the terms “media”, “active media”, and“sorption media” are used interchangeably.

As used herein, the term “sorption” includes adsorption, chemicaladsorption (i.e., chemisorption), absorption, and/or physical adsorption(i.e., physisorption).

When used in connection with a media and/or support substrate, the term“unused” refers to a material that is in its virgin or unspent form. Incontrast, when used in connection with a media and/or support substrate,the term “used” or “spent” refers to a material that has been employedin one or more processes for which the material was intended. Forexample, a used (or spent) Claus catalyst is a catalyst that has beenemployed in a Claus process for recovering sulfur from hydrogen sulfide.

As used herein, the term “stream” describes a quantity of fluid having acontaminant species. A fluid stream may include a flowing fluid, but canalso describe a static quantity of fluid. Thus, the sorbents describedherein can be disposed in a moving quantity of fluid to effectcontinuous contaminant removal. Likewise, the sorbents can also be addedto a fixed quantity of fluid to effect contaminant removal in a batchfashion.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of various embodiments of the presentinvention, reference is now made to the following descriptions taken inconnection with the accompanying drawings in which:

FIG. 1 shows a method of making an embodiment of a sorption media;

FIG. 2 shows an illustrative process for preparation of a pre-coatfilter;

FIG. 3 shows an illustrative process for use of a pre-coat filter havingan active media entrained;

FIG. 4 shows an illustrative process for use of an active media toreduce contamination levels in a fluid;

FIGS. 5A and 5B show another illustrative process for the use of anactive media to reduce contamination levels in a fluid;

FIG. 6 shows a complete ESCA scan of a fresh Maxcel 740 catalyst(untreated and unused);

FIG. 7 shows an ESCA scan of a fresh Maxcel 740 -based sorption mediaafter it has been doped and reacted (treated and unused);

FIG. 8 shows an ESCA scan of a fresh Maxcel 740 -based sorption mediaafter it has been doped, reacted (treated and unused), and washed withwater;

FIG. 9 shows an ESCA scan, in the aluminum region, of a fresh Maxcel 740catalyst (untreated and unused);

FIG. 10 shows an ESCA scan, in the aluminum region, of a fresh Maxcel740 -based sorption media after it has been doped and reacted (treatedand unused);

FIG. 11 shows an ESCA scan of a spent alumina catalyst that was usedduring the manufacture of hydrogen peroxide (untreated and used);

FIG. 12 shows an ESCA scan of a sorption media that is based on a dopedspent alumina catalyst from the manufacture of hydrogen peroxide(treated and used);

FIG. 13 shows an ESCA scan of a sorption media that is based on a dopedspent alumina catalyst from the manufacture of hydrogen peroxide(treated and used), after being washed with water;

FIG. 14 shows an ESCA scan of a fresh Maxcel 740 -based sorption mediaafter it has been doped and reacted (treated and unused);

FIG. 15 shows an ESCA scan of a fresh SULFATREAT XLP-based sorptionmedia (untreated and unused);

FIG. 16 shows an ESCA scan of a fresh SULFATREAT XLP-based sorptionmedia after it has been reacted (treated and unused);

FIG. 17 shows an ESCA scan of a fresh SULFATREAT XLP-based sorptionmedia after it has been reacted (treated and unused), after being washedwith water;

FIG. 18 shows an ESCA scan of a spent SULFATREAT XLP-based material(used and untreated);

FIG. 19 shows an ESCA scan of a spent SULFATREAT XLP-based sorptionmedia (used and treated); and

FIG. 20 shows an ESCA scan of a fresh Maxcel 740 -based sorption mediaafter it has been mixed with sulfur and reacted (unused and treated).

DETAILED DESCRIPTION

A sorption media for the reduction of one or more contaminants from afluid stream is described, as well as methods of making the sorptionmedia and using the same.

In one aspect, a sorption media for reducing contaminant levels in afluid stream is described. The sorption media includes a supportsubstrate or matrix bound to or linked with an active compound.Non-limiting examples of support substrates or matrixes include iron-,alumina-, silicon-, titanium-, and carbon-based substrates. In someembodiments, the alumina-based matrix includes Claus catalyst. In somespecific embodiments, the Claus catalyst is virgin Claus catalyst. Inother specific embodiments, the Claus catalyst is spent Claus catalyst.In other embodiments, the alumina-based matrix includes other non-Clauscatalyst. In other embodiments, the media includes an iron-based matrix.

Non-limiting examples of the active compounds include sulfur,aluminum-sulfur compounds, iron-sulfur compounds, ammonium sulfate,ferric chloride, copper sulfate, copper chloride, and/or other variousmetal salts. Iron-sulfur compounds include, but are not limited to,ferric sulfate, ferric sulfite and ferrous sulfide. Non-limitingexamples of contaminants include arsenic, mercury, and D-block metalsand/or heavy metals, including, but not limited to, barium, strontium,selenium, uranium, lead, titanium, zinc and/or chromium. The reductionof other metal contamination levels is contemplated. In someembodiments, the media reduces contaminant levels from the fluid streamby one or more of adsorption, chemical adsorption (i.e., chemisorption),absorption, and/or physical adsorption.

In some embodiments, the fluid stream includes an aqueous fluid. In somespecific embodiments, the aqueous fluid includes one or more of groundwater, process waste water from a chemical process, and others. Othernon-aqueous fluid streams are also contemplated. Likewise, the variousmedia described herein can be used to reduce contaminated in non-liquidfluid streams.

In some embodiments, the media enable the reduction of arsenic andmercury levels in aqueous liquid streams. Other embodiments of the mediaenable the reduction of D-block metals and/or heavy metal levels,including, but not limited to, strontium, uranium, lead, and/orchromium.

Without being limited to any particular theory, it is believed that inthe sorption media described herein, the active compound is bound orlinked to the support substrate or matrix so that the loss of the activecompound into the fluid stream is reduced or minimized. For example, itis thought that, in some implementations, the active compound chemicallyinteracts with the support substrate in such a way as to become at leastpartially integrated with the support substrate. In other words, thesupport substrate and active compound form a chemical compound thatholds the active compound in place. Thus, the support substrate andactive compound may form a chemical bond (e.g., a covalent bond and/oran ionic bond). In other implementations, it is believed that otherattraction forces reduce the mobility of the active compound. Forexample, the active compound and support substrate may exhibit one ormore of dipole-dipole interactions, hydrogen bonding, and/or dispersionforces.

Further still, it is also believed that mechanical forces can play arole in reducing the mobility of the active compound and/or moleculesand/or complexes formed by interactions between the active compound andsupport substrate. For example, the active compound and/or the complexesformed can be lodged into small pores in the surface of the supportsubstrate, thereby confining the material within the pores. Similarly,the techniques described herein are believed to create active surfaceswithin the pore structure of the support substrate.

Due to the formation of such a bond or linkage, the active compoundcannot be completely solvated by the fluid molecule and, thus, thedissolution rate of the active compound is significantly reduced.Moreover, the bond or linkage also resists physical forces of fluids incontact with the media that would otherwise wash the active compoundfrom the surface of the media. Thus, as used herein, the dissolutionrate of the active compound describes the rate of loss of the activecompound from the media due to both chemical and physical phenomena. Insome embodiments, the active compound for sorption of mercury isbelieved to be ferric sulfate, ferric sulfide, aluminum sulfate, and/oraluminum sulfide. Meanwhile, it is thought polarized iron (e.g., iron ina salt complex) is effective for sorption of arsenic. While ferricsulfate and ferric sulfide dissolve in water under standard conditions,it is believed that, by using the method described herein, ferricsulfate or ferric sulfide can be bound or linked to the supportsubstrate or matrix comprising, e.g., alumina and/or iron. This bondallows the linked iron-sulfur and/or aluminum-sulfur compounds to beexposed to an aqueous liquid stream while dissolving into the liquidstream at a reduced rate compared with free iron-sulfur and/oraluminum-sulfur compounds in liquid not bound to any support substrate.This enables the active compound, e.g., iron-sulfur and/oraluminum-sulfur compounds, to act upon contaminants in an aqueous streamwithout significant loss of the sulfate and/or sulfide species into thestream itself. In general, the embodiments described herein enable anotherwise soluble compound to be attached to the surface or interior ofthe support substrate or matrix in a way that maintains the activecharacteristics of the active compound while reducing the amount of theactive compound washed away during use.

The scope of the invention is not limited to the use of ferric sulfate,but includes other compounds, for example, ferric chloride, ammoniumsulfate, copper sulfate, copper chloride, elemental sulfur, hydrogensulfide, and others. In some implementations, the active compound formsthe bond and/or link with the support substrate and, also, provides thesorbing activity of the media. In other implementations, the activecompound forms a bond and/or link with the support substrate, and anadditional reaction step is performed to chemically change a portion ofthe active compound to provide sorbing activity (e.g., copper chlorideis bonded to a support substrate and later reacted with hydrogen sulfideto form a copper-sulfur species bonded to the substrate).

In some embodiments, iron-based substrates found in used or unusedcommercial materials for treating natural gas to remove sulfurcompounds, e.g., SULFATREAT XLP, Iron Sponge, and other similarmaterials, is used as the support substrate for the media as describedherein. Some of these materials include iron oxides, e.g., ferric oxideand triferric oxide.

In another aspect, a method for making a sorption media for thereduction of contaminant levels from fluid streams is also described.The method includes selecting a support substrate or matrix, optionally,providing a doping mixture comprising an active compound, and,optionally, contacting the selected support substrate or matrix with thedoping mixture to form a doped matrix mixture, and reacting the dopedmatrix mixture at a predetermined temperature and predeterminedatmospheric environment for a predetermined duration to form an activemedia, wherein the active compound is bound or linked to the supportsubstrate. FIG. 1 shows an overview of a method 100 of making of asorption media in some embodiments. A support substrate, e.g., a virgin,spent, or recycled substrate, is selected as the base for the media(step 110). In some embodiments, the substrate is a used catalyst from anatural gas or other sweetening process. Examples include, but are notlimited to, iron doped, virgin, or recycled Claus catalysts, as well asaerogels, titanium dioxide, iron-based natural gas treatment catalysts(e.g., SULFATREAT and others), and alumina-based catalysts. In addition,an active compound is selected and optionally dissolved in anappropriate solvent to form a doping mixture (step 120). Solvents caninclude aqueous solvents and/or organic solvents.

In some embodiments, the substrate may also be reduced in size prior tothe drying, doping, and reacting steps using, e.g., roller, ball, orimpingement mill equipment. Next, the selected substrate base and dopingmixture are contacted and held in a temperature and humidity controlledenvironment for a selected duration to form a doped substrate (step130). In some embodiments, the temperature is held between 30-90° C.,the relative humidity varies between 0-40%, and the duration variesbetween 10-45 minutes. A sufficient amount of doping mixture is put incontact with the substrate base so that no compound of the dopingmixture is a limiting reagent in any reaction between the doping mixtureand substrate. The material (the doped substrate) is then processed byan intermediate step, during which it can be dried and/or surfacetreated, for example, by washing in water, acetone, or other solventand/or further heating or cooling (step 140). For example, the dopedsubstrate can be heated to a temperature between 100-300° C. for 1-4hours. The material may also be cooled as part of this step 140.

In some embodiments, after drying and/or heating the substrate, a dopingagent (if one is present) and the substrate are reacted under controlledtemperature and atmospheric conditions, which may include various gases,as set forth below, for a selected duration to form an activated media.The specific examples set forth herein are illustrative only, asdifferences is doping agents, reactant gases, reaction duration, etc.will achieve different effects on the various support substrates. Theseeffects can be controlled, by manipulating the overall process, toachieve different levels of activity of the media that are effective insorbing particular contaminants (step 150). Non-limiting examples ofdoping agents include various gases and transitional metals. If thesubstrate has been doped, then it may require an additional drying step.In some embodiments, the media is then put in a chamber (if the chamberhas not been used already for doping and conditioning of the base) andexposed to various gasses. The gases include, but are not limited to,H₂, Nitrogen, and H₂S gases. In some embodiments, the temperature iscontrolled to between 100-500° C. and the atmosphere comprises any oneor a mixture of hydrogen sulfide (e.g., 2-15 vol %), hydrogen (e.g.,2-15 vol %), air (e.g., 5-100 vol %), water, and/or nitrogen (e.g.,10-100 vol %). The duration varies between 1-6 hours. A sufficientamount of the gas mixture is supplied to the substrate (and dopingagent, if present) during the reaction so that none of the components ofthe gas mixture are a limiting reagent in any reaction that takes placeduring the reaction step. In some embodiments, the media is furtheroptionally doped with various transition metals such as, but not limitedto zinc, strontium and copper to reduce or eliminate inorganiccontaminants, including, but not limited to heavy metals such as mercuryand arsenic from waste streams.

In some other embodiments, the doping agent is not added and thereaction conditions are selected to form the active ingredients on thesurface of the substrate. In those embodiments, the active agent iscreated chemically on the surface of the substrate by, e.g., exposure toa mixture of gases in a reactive environment.

The material is then allowed to cool and is processed to achieve adesired particle size (step 160). In some embodiments, the active mediacan be crushed to a certain particle size using, e.g., roller, ball, orimpingement mill equipment. In some embodiments, the active media iscrushed or milled to a particle size in the range of 12-325 mesh. Theactive media may also be combined with other materials (step 170) toform a sorption media blend. Other materials suitable for blend with theactive media include, but are not limited to, another active media withthe same or different support substrate or active compound. In someembodiments, the active material described herein can be used as amixture with other sorbing material such as those described in U.S. Pat.No. 7,341,667, entitled Process For Reduction Of Inorganic ContaminantsFrom Waste Streams, filed Oct. 29, 2004, and issued Mar. 11, 2008; inU.S. Pat. No. 7,479,230, entitled Process For Reduction Of InorganicContaminants From Waste Streams, filed Feb. 1, 2008, and issued Jan. 20,2009; and in U.S. Pat. No. 7,449,118, entitled Process For Reduction OfInorganic Contaminants From Waste Streams, filed Feb. 1, 2008, andissued Nov. 11, 2008.

The steps 120-160 set forth in method 100 can be performed in a varietyof sequences, and some steps may be omitted or repeated. For example,creation of a doping mixture and contacting the selected substrate withthe mixture (steps 120 and 130) may be omitted. Instead, the selectedsubstrate can be treated with reactant gases alone to form an activemedia (step 150). In contrast, multiple doping contact steps (using thesame doping agent or a different doping agent) can be performed. Theactive material can also be processed to achieve a desired particle sizebefore and/or after any doping and/or reactant steps (step 160).

Moreover, by controlling the conditions of manufacture, as disclosedherein, it is possible to adjust the rate at which the active compoundis lost from the media. For example, rate of loss of ferric sulfate, interms of iron, ranges from over 300,000 μg-Fe/L of wash water to under200 μg-Fe/L of wash water. The retention of the active compound can alsobe observed by visual confirmation of color bodies and a brown/orangecolor, or lack thereof, in the wash water.

It is believed method 100 enables many different active compounds,including flocculating materials, to be linked to or bound with a stablesupport substrate or matrix to form an active media. The use of theactive media manufactured using methods disclosed herein simplifieswaste streams processing and enables easier management of waste productsby sorbing contaminants onto the matrix. The active compounds disclosedherein can be used to manufacture the active media according to themethod disclosed herein. In addition to various active compounds,different matrices or support substrates disclosed herein may be used asa base for the manufacture of the active media, using the methoddisclosed herein. For example, it is believed that aluminum, titanium,and/or silicone matrices can be used in place of the alumina and irondisclosed herein. The selection of active compounds, in combination withan appropriate base, enables a sorption media to be tailored to sorb atarget contaminant or group of contaminants, e.g., strontium, uranium,lead, and/or hexavalent chromium.

In yet another aspect, the method of using the active media to reducecontaminant levels in fluid stream is described. The method comprisesproviding an active media as described herein and contacting the activemedia with a fluid stream containing a contaminant. The contaminant caninclude any one or more of the contaminants as described herein.

In some embodiments, the active media disclosed herein may be used incombination with other media to create tailored treatments for specificwater problems. In some specific embodiments, an iron-based active mediacan be mixed with an alumina-based active media to form a mixture ofactive media. The mixture of active media can be used to reduce morethan one type of contaminant level effectively, depending on thespecificities of different active media for certain contaminants. Forinstance, it is surprisingly discovered that an iron-based active mediamixed with an alumina-based active media can effectively reduce mercuryand arsenic levels in an aqueous stream.

The media may also be used directly in fluid streams and removed byfiltration. The media may also be mixed with clays to form slurry wallsor liners to support remediation and to sorb trace metals that cannormally leach from areas of contamination. In general, e.g., any one ormore of the active medias described herein can be incorporated intoproducts produced by AquaBlok, Ltd. of Toledo, Ohio.

For example, media #4, described below, was incorporated into anAquaBlok material at a level of 5 wt % media. A ball jar test wasperformed using 370 ml of 1000 ppb mercury contaminated water to which527 g of the AquaBlok/media mixture had been added. After allowing thejar to sit for approximately 48 hours, supernatant liquid was drawn offof the top of the jar and filtered through a 1.2 μm filter and analyzedfor mercury concentration. The filtered water sample contained about 22ppb mercury. After allowing the jar to sit a total of about 120 hours,supernatant liquid was again drawn off, filtered, and analyzed. Thefiltered water sample contained less than 5 ppb mercury.

In some embodiments, the active media as described herein can be used toform a continuously regenerating treatment system. As described above,the incorporation of the active compound, e.g., ferric sulfate, into themedia base, e.g., an alumina or iron matrix, reduces the amount ofactive component dissolved in use. This permits contaminants, heavymetals, color agents, and other undesirable materials in a fluid streamto accumulate on or adhere to the surface of the media and/or very smallexternal features of the media to be removed. Thus, after use, a spentmedia is created that can be removed from a fluid treatment system anddisposed of. For example, when the ferric sulfate/alumina media is usedto treat an aqueous stream containing heavy metal contamination, thespent media is non-hazardous (per Toxicity Characteristic LeachingProcedure test). A typical concentration of heavy metal on the media isfrom 20 to over 10,000 mg/g-media. Metal levels reduced can includearsenic and mercury and, it is thought, a wide range of metals includinglead, uranium, selenium, chromium, and other transition metals.Moreover, the use of the media is believed to be effective on a widerange of ionic and complex metal forms, including the reduction of metallevels from ground water.

In addition to treating a wide range of contaminants, the media asdescribed herein shows an increase in the speed with which contaminantscan be reduced in a fluid stream as compared to alternatives. In oneillustrative embodiment, in the application of treating contaminatedground water with 3000 ppt mercury and 25 ppb arsenic, activated carbonrequired 90 minutes of contact time to reduce the mercury to less than20 ppt. In comparison, a SULFATREAT XLP-based media, as describedherein, needs less than 60 seconds to reduce the similar amount of themercury contaminant. This increased speed of action over known treatmentmaterials permits the use of the media disclosed herein in a wide rangeof applications not typically permitted in water service due to theamount of time needed for water to be in contact with conventionalmaterials. Using the media, techniques, and methods disclosed herein,canisters and pre-coat filters can be used to take advantage of themedia's brief effective contact time. This further enables the use ofthe media in continuous flow fluid bed applications and in foulingservices, including, but not limited to, ground water treatmentservices. The ability to be used in fouling services allows forrelatively high levels of contamination to be treated directly, withoutthe need to dilute the contaminated stream prior to contaminationreduction. Furthermore, the speed and high capacity allow theiron-matrix media to be used to prevent migration of metals through clayliners in remediation services. Additionally, the media described hereincan be used as an active ingredient in activated sludge water treatmentsystems.

Moreover, the contaminant-sorption capacity of the media is greater thanthat of other materials used to treat contaminated fluids. For example,activated carbon was only effective at removing contaminants from fourbed volumes of contaminated ground water (1 gallon of water beingtreated by 1 gallon of activated carbon), whereas the SULFATREATXLP-based media described herein remained effective for over 1000 bedvolumes, and, in some implementations, remained effective for about 5000bed volumes. In other illustrative embodiments of the media describedherein, the media remained effective for over 18,000 bed volumes and, insome implementations, over 27,000 bed volumes.

In addition to the benefits set forth above, the media, techniques, andmethods disclosed herein include other advantages, as follows. A widerange of spent activated alumina, used iron sponge or other spentmaterial is currently disposed of in landfills, which has a detrimentalenvironmental impact. As described herein, such material can be used asa support substrate or matrix for the various types of active mediadisclosed herein. In some embodiments, spent alumina and used ironsponge material can be diverted from landfills to produce additionalactive media, thereby reducing the environmental impact that the spentalumina would have otherwise had.

The active media as described herein has a higher level of activity ascompared to activated carbon. Thus, less media and smaller equipment canbe used to treat certain fluid streams as compared to activatedcarbon-based systems. For example, a treatment system using the ferricsulfate/alumina media described herein requires about one-tenth the sizeof footprint required for an activated carbon-based system for treatinggroundwater with 2.5 ppb mercury contamination to a level of less than20 ppt. Moreover, the higher activity of the media as compared toactivated carbon permits the use of about one-tenth the amount of mediain a treatment system. For example, in the ground water exampleimmediately above, the media has an active life of about 1000 bedvolumes, as compared to about four bed volumes for activated carbon.

Further, it is believed that embodiments of the disclosure permit theactive compound to retain desirable characteristics, e.g.,electrochemical and/or properties, while keeping the compound bound tothe matrix. Thus, the active compound can act as a flocculation agentfor contaminants, in that it can bind the contaminants, withoutrequiring the additional steps of settling and filtering that typicalflocculation agents require.

FIG. 2 shows an illustrative process 200 for preparation of a pre-coatfilter using any of the medias described herein as well as the treatmentmaterials described in the patents incorporated above. A vessel 210 isfilled with a slurry mixture of 300 grams of active media of size 325mesh in one gallon of water. A pump 220 circulates the slurry mixturefrom vessel 210 through a pre-coat filter of 30 microns or less at arate of about 1 gallon per minute. The circulation continues until theslurry mixture is approximately clear, indicating that a quantity of theactive media has been entrained into the pre-coat filter. The filter maythen be used to reduce contaminant levels as set forth herein.Optionally, after the reduction of the contaminant levels, the spentmedia can be removed and/or replaced by a fresh active media.

FIG. 3 shows an illustrative process 300 for use of a pre-coat filterhaving an active media in a bed (e.g., any of the media set forth in theexamples below). A contaminated stream 310 includes 2.5 ppb mercury and25 ppb arsenic in water. Contaminated stream 310 is passed through apretreatment filter 320 of 10 micron or less to remove particulatecontaminants at a rate of 333 ml/min. The stream is then passed thoughpre-coat filter 330, prepared in accordance with process 200. Pre-coatfilter 330 is expected to reduce the levels of mercury and arsenic inthe water, as set forth above. An effluent stream 340 is expected tocontain less than 20 ppt mercury and no detectable arsenic. It isunderstood that the contamination levels, contamination reductionamounts, and flow rates are illustrative only, and greater or lesservalues are contemplated.

FIG. 4 shows an illustrative process 400 for use of media #1, describedbelow, to reduce contamination levels in a fluid. A vessel 410 containscontaminated water including 3000 ppt mercury and 25 ppb arsenic. A pump420 passes the contaminated water from vessel 410 through a column 430containing media #1. In one implementation, column 430 is about 25.08centimeters long, having an inner diameter of about 0.5 centimeters, andcontains about 4 grams of active media filling a section of the columnabout 4 centimeters in length. During continuous operation for at least7 days at a flow rate of about 4 ml/minute, an effluent stream 440contains less than 20 ppt mercury and no detectable arsenic. It isunderstood that the particular media used, contamination levels,contamination reduction amounts, and flow rates are illustrative only,and greater or lesser values are within the scope of the invention.

FIGS. 5A and 5B show a side view and a top view, respectively, of anillustrative apparatus 500 for use of any of the media described hereinto reduce contamination levels in a fluid. A vessel 505 is continuouslyfed a contaminated fluid from inlet 510 to maintain a level ofcontaminated fluid in vessel 505. A drum 515 is partially submerged inthe fluid in vessel 505 and rotates about a central axis. Drum 515 has aporous surface that has been coated with one or more selected media.Drum 515 also has an outlet 520, which is in fluid communication withthe interior of the drum, and may include additional structures insidethe drum, to allow fluid inside drum 515 to exit the drum. Vessel 505also has a media inlet 525 for feeding a slurry of media in a fluid intovessel 505. In one illustrative implementation, the media can be addedto the contaminated fluid upstream of apparatus 500 so that the mediaenters vessel 505 via inlet 510 along with the contaminated fluid.Apparatus 500 also includes a scrapper plate 530 in contact with drum515.

As drum 515 rotates, a vacuum is drawn on outlet 520. The vacuum bringscontaminated fluid through the porous surface of drum 515, on which isdisposed the active media. Meanwhile, media that has contacted thecontaminated fluid, used media 535, is removed from the surface of drum515 by scrapper plate 530. Additional fresh active media, which wasadded by media inlet 525, is added to the surface of drum 515 when thebare drum surface resubmerges in the contaminated fluid in vessel 505.In this way, a continuous flow of contaminated fluid is treated with acontinuously renewing supply of active media. The used media 535 can beremoved for disposal.

In one or more embodiments, the methods and treatments as describedherein increase the sulfate, sulfite, and sulfide content of the media.One analytical technique for measuring the elemental composition of amaterial is an ESCA (Electron Spectroscopy for Chemical Analysis) scan.An ESCA scan is an analytical technique used to look at the surface ofmaterials. An ESCA scan is sensitive to the chemical state of thematerial being analyzed. For example, an ESCA scan can reveal thepresence and relative proportions of sulfate, sulfide and sulfite in amaterial. Changes in horizontal position on the scan indicate a chemicalshift, described in greater detail below. Changes in height indicaterelative changes in amount of a particular substance in the materialbeing analyzed. Chemical composition information provided herein isgiven in mol %.

In some implementations of the invention, the sulfate and sulfidecontents of various support substrates increase in the following order:(unused and untreated material)<(unused and treated material)<(used anduntreated material)<(used and treated material). In some embodiments, aused catalyst is treated with one or more H₂S, H₂, N₂, and/or air, whichresults in a significant increase in the sulfate and/or sulfide content.As used herein, the term “treated” refers to a catalyst (or othersupport substrate or matrix) that has been processed according to any ofthe illustrative embodiments of method 100 of making a sorption media.

Without being limited by any particular theory, it is believed thatsulfur compounds act as the active species in reducing metal contaminantlevels in fluid streams and the sulfate and sulfide or other sulfurcontaining compounds contained within the various medias correlate withthe sorbing capacity of the media. The sorbing capacity increases withthe increase of the contents of sulfate, sulfide, or other sulfurcontaining compounds. In one or more embodiments, the sulfide contentcontributes to a greater extent to the sorbing capacity of the mediathan the sulfate content. The content of sulfate and sulfide or othersulfur-containing compounds can be determined by measuring the molarpercentage of sulfur in the sorption media. The molar percentage ofsulfur can be calculated by the following formula:Sulfur mol %=moles of sulfur atom in the media/total moles of all theatoms in the media  (Formula I).

In some embodiments, the sulfur content is more than about 5.0 mol %. Insome embodiments, the sulfur content is more than about 7.0 mol %. Insome embodiments, the sulfur content is more than about 9.0 mol %.

The capacity of the sorption media can be measured by the amount ofmetal in the fluid stream absorbed by the media. In some embodiments,the capacity of the sorption media is measured by the weight of mercury(mg) in the aqueous stream absorbed by the media (in kilograms). Thecapacity of the sorption media can also be measured by the amount ofinorganic mercury absorbed by the sorption media. Further still, thecapacity of the sorption media can be measured by the amount of ionicmercury absorbed by the sorption media.

Depending on the species of mercury in the fluid stream (e.g., inorganicor ionic), a sorption media comprising different active compounds can beutilized to effect efficient level reduction of the multiple mercuryspecies. In some embodiments, the fluid stream contains inorganicmercury and a sorption media including a sulfide species is used forreducing mercury levels. In other embodiments, the fluid stream containsionic mercury and sorption media comprising sulfate is used for reducingthe mercury levels.

Thus, another aspect of the invention includes identifying the type ofcontaminant species present in a fluid that is to be treated andselecting the active compound to be bonded or linked to a media that isbest suited for reducing the level of the identified contaminant. Forexample, if it is determined that a fluid to be treated contains anionic mercury contaminant, then a media including iron sulfate, aluminumsulfate, and/or copper sulfate (e.g., media #1 described below) isselected as best suited for removing said contaminant. In contrast, ifthe fluid contains both ionic and inorganic mercury contaminants, then amedia including both sulfate and sulfide species (e.g., media #3described below) is selected as best suited for removing saidcontaminants. Further still, a combination of media can be selected foruse in treating a contaminated stream that has both ionic and inorganicmercury contamination wherein at least one media of the combinationincludes a sulfate species and at least one other media of thecombination includes a sulfide species (e.g., media #1 and media #6described below).

The following media and specific parameters for its manufacture areprovided as illustrative examples of the media that can be prepared andused by the techniques disclosed herein. It is understood that theseexamples are illustrative only, and other media and specific parametersfor their manufacture are within the scope of the invention. Forexample, various temperatures, pressures, durations, componentconcentrations, materials, and material quantities are specified. It isunderstood that these parameters are illustrative and may be varied toachieve the desired media compositions.

Moreover, the specific parameters set forth in Tables 1-3 below describeprocesses for making the illustrative media in relatively smallquantities. While it is thought these processes can be directly scaledto produce relatively large quantities of the desired media, othertechniques for making relatively large quantities may use parametersthat differ from those set forth in the Tables. Examples of thevariability of such parameters are provided in the descriptions thatfollow.

In the examples below, a contaminant capacity of the media is provided.In order to determine the contaminant capacity, two methods were used.In the first method, called the “spin test” herein, 0.5 grams of theparticular media was mixed with 0.25 liters of a standard solution(e.g., water containing a known initial concentration of a contaminantspecies). The media and standard solution was stirred for about fiveminutes at approximately 500-800 RPM using a magnetic stir plate. Themedia/solution mixture was then filtered through a 1.0-1.2 μmfilter/vacuum apparatus (e.g., 47 mm, 1.2 μm Versapor Membrane DiscFilter with vacuum filtration). A contaminant analysis was thenperformed on the collected filtrate, and the media capacity determinedby multiplying the difference between the initial contaminantconcentration and final contaminant concentration by the volume ofstandard solution and then dividing by the weight of media used.

In the second contaminant capacity testing method, called the “columntest” herein, a glass column that is approximately 1 cm inner diameterand 46 cm high is used. The column is filled with enough media to form apacked section of about 8-9 cm in height. Approximately 1 liter of astandard solution was pumped through the column at about 4 ml/min. Thesolution that passed through the column was collected, and thecontaminant concentration therein was determined. The media capacity isdetermined by multiplying the difference between the initial contaminantconcentration and final contaminant concentration by the volume ofstandard solution and then dividing by the weight of media used to formthe packed section. Other column configurations, media quantities, andflow rates were also used to determine media contaminant capacity inwhich the contact time between the standard solution and media wasapproximately 2 minutes. In some tests, the flow of standard solutionwas halted before the media's ultimate capacity was achieved. In suchcases, the capacity is reported as being at least that capacity achievedat the moment the test was halted.

All capacity testing data disclosed herein describes a media capacityfor an ionic mercury species.

Illustrative Example Media #1

An active media, media #1, was prepared according to the methoddescribed in Table 1. The representative steps of method 100 are alsolisted in Table 1.

TABLE 1 Illustrative parameters for manufacture of media #1 Media base(step 110) Maxcel 740 virgin alumina Claus catalyst; target Net LOI at1000° C. <7%; macro porosity at 750 Å of greater than 0.1 cc/g Mediasizing (step Media was ground to sizing of 12 × 40 mesh 160) prior tofurther processing Active compound and 10 grams ferric sulfate (purityof 99.9%) was solvent (step 120) dissolved in 100 ml distilled water at70° C. Media preparation for Media substrate was dried at 100-200° C.for doping (step 140) 60-120 minutes; media was cooled to ambienttemperature in air Contact temperature, The dopant mixture was contactedwith the humidity, and contact time dried substrate at 40° C. for 10-20minutes until the (step 130) dopant was absorbed (e.g., the mediaappeared wet) Wash liquid, drying No wash step; doped substrate wasdried for 2 time, and drying temperature hours at 200-400° C. (step 140)Second doping (step The dried media was re-doped with 10 grams 130)ferric sulfate (purity of 99.9%) dissolved in 100 ml distilled water at70° C. Wash liquid, drying No wash step; doped substrate was dried for 2time, and drying temperature hours at 100-200° C. (step 140) Reactiontemperature, Media heated to 200° C. in the presence of 90 atmosphericcomposition, and vol % N₂ and 10 vol % H₂ at a range of pressures up toreaction duration (step 150) 10 psig Cooling (step 150) Media was cooledin the presence of H₂ and N₂ at reaction ratios until the media reached70° C.

FIG. 6 shows a complete ESCA scan 600 of a sample of virgin Maxcel 740alumina Claus catalyst (untreated and unused), which is available fromPorocel of Little Rock, Ark. Maxcel 740 is an iron-doped aluminacatalyst. As shown in FIG. 6, there is no sulfur in this virgincatalyst, which would appear in area 605 (in approximately the 176-154eV range). The composition of the virgin catalyst includes approximately72.6% oxygen, 24.5% aluminum, 0.5% iron, and 0.5% sodium. The capacityof this material as a media was 0 mg-mercury/kg-media.

After the virgin catalyst was treated according to method 100 using theparameters set forth in Table 1, an ESCA scan was performed on a sampleof the resulting media #1. FIG. 7 shows an ESCA scan 700 of a sample ofmedia #1. The ESCA scan indicates that at least one sulfur species ispresent, as shown by peak 705. The composition of a sample of media #1includes approximately 66.8% oxygen, 10.6% aluminum, 5.7% sulfur, and9.6% iron. The sulfur exists as nearly 100% sulfate species. Thecapacity of a sample of media #1, as determined by a spin test, wasdetermined to be about 340 mg-mercury/kg-media.

FIG. 8 shows an ESCA scan 800 of a sample of media #1 after it has beenwashed with water. The ESCA scan shows that the sulfur species was stillpresent after washing (peak 805), thereby suggesting the sulfur speciesis bound or linked to the support substrate in some way. The compositionof a sample of media #1 after washing includes approximately 68.8%oxygen, 24.2% aluminum, 1.4% sulfur, and 1.4% iron. The sulfur exists asabout 90% sulfate species and 10% sulfide species. The capacity ofsamples of this media #1 after washing, as determined by a spin test,ranged from about 330 mg-mercury/kg-media to about 724mg-mercury/kg-media and about 436 mg-arsenic/kg-media. One sample of themedia #1 demonstrated a ferric sulfate loss of 2000 μg-Fe/L of washwater.

FIG. 9 shows another ESCA scan 900 of a sample of virgin Maxcel 740alumina Claus catalyst (untreated and unused), focusing on the region ofabout 88-68 eV. Likewise, FIG. 10 shows another ESCA scan 1000 of asample of media #1, also focusing on the region of about 88-68 eV. Thesetwo scans show a shift in the aluminum peak from about 73.333 eV in thevirgin Maxcel 740 alumina sample (peak 905) to about 74.060 eV in themedia #1 sample (peak 1005). This energy shift is believed to be due tointeractions between the alumina support substrate and the reactantsintroduced by the various implementations of method 100, e.g., asperformed in accordance with the parameters set forth in Table 1. Forexample, sulfur may be substituting for oxygen in part of the aluminaand/or iron oxide matrix of the support substrate (e.g., due to acovalent and/or ionic bond). It is theorized that this interaction isresponsible, at least in part, for the reduction in the loss of theactive compound from the support substrate when the media is used totreat contaminated fluids and the resulting retention of the contaminantspecies.

As stated generally herein, the parameters in Table 1 can be varied toachieve desired media. For example, during the reaction step (150), thehydrogen concentration can be varied from 3-10 vol %, and the nitrogenconcentration can be varied from 50-95%. Also, hydrogen sulfide, inconcentrations varying from 2-5 vol %, and air, in concentrationsvarying from 0-35 vol %, can also be used. Furthermore, the reactiontemperature can vary from 150-400° C., and the reaction time can varyfrom 0.5-2.0 hours. The active compound can vary from 5-20 wt % in thedopant mixture.

Illustrative Example Media #2

An active media, media #2, was prepared according to certain steps ofthe method described in Table 1. However, a spent alumina catalyst thatwas used in the production of hydrogen peroxide was used as the mediabase in place of the Maxcel 740 material (the alumina catalyst was a lowsodium Alcan catalyst available from Arkema, Inc. of Philadelphia, Pa.).In addition, the second doping step and wash steps were omitted. Also, amixture of hydrogen and hydrogen sulfide was used during the reactionstep in place of the nitrogen and hydrogen. All other steps in theprocess remained essentially the same as used to produce media #1. FIG.11 shows a complete ESCA scan 1100 of a spent alumina-based catalystused in the product of hydrogen peroxide. As shown in FIG. 11, there isno sulfur in this used catalyst, which would appear in area 1105 (inapproximately the 176-154 eV range). The composition of the spentcatalyst includes approximately 62.1% oxygen, 25.8% aluminum, 11.8%carbon, and 0.3% sodium. The capacity of this material as a media was 0mg-mercury/kg-media.

After the spent alumina catalyst was treated according to method 100using the parameters set forth in Table 1 (excluding the omitted steps),an ESCA scan was performed on a sample of the resulting media #2. FIG.12 shows an ESCA scan 1200 of a sample of media #2. The ESCA scanindicates that at least one sulfur species is present, as shown by peak1205. The composition of a sample of media #2 includes approximately 53%oxygen, 16% aluminum, 1.6% sulfur, 2.8% iron, and 26.7% carbon. Thesulfur exists as nearly 100% sulfate species. The capacity of a sampleof media #2, as determined by a spin test, was determined to be about221 mg-mercury/kg-media.

FIG. 13 shows an ESCA scan 1300 of a sample of media #2 after it hasbeen washed with water. The ESCA scan shows that the sulfur species wasstill present after washing (peak 1305), thereby suggesting the sulfurspecies is bound or linked to the support substrate in some way. Thecomposition of a sample of media #2 after washing includes approximately58% oxygen, 16.3% aluminum, 1.6% sulfur, 1.3% iron, and 22.8% carbon.The sulfur exists as about 100% sulfate species. The capacity of asample of this media #2 after washing, as determined by a spin test, wasabout 113 mg-mercury/kg-media.

Illustrative Example Media #3

An active media, media #3, was prepared according to the methoddescribed in Table 2. The representative steps of method 100 are alsolisted in Table 2.

TABLE 2 Illustrative parameters for manufacture of media #3 Media base(step 110) Maxcel 740 virgin alumina Claus catalyst; target Net LOI at1000° C. <7%; macro porosity at 750 Å of greater than 0.1 cc/g Washliquid, drying The substrate is dried for up to 1 hours at 150° C. time,and drying temperature in a vacuum (step 140) Reaction temperature, Thesubstrate is heated to 200° C. in up to 30 atmospheric composition, andvol % H₂S, 5 vol % H₂, and 75 vol % N₂ at a range of reaction duration(step 150) pressures up to 10 psig for up to 5 hours Cooling (step 150)The media is cooled in the presence of H₂S, H₂, and N₂ at reactionratios until the media is 70° C. Final media size (step Media is sievedto isolate suitable particles in 160) the 12 × 40 range; largerparticles are ground to particles approximately 12 × 40, 40 × 60, −100mesh; substrate/ media may be ground before or after the reaction andcooling steps

After the virgin catalyst was treated according to method 100 using theparameters set forth in Table 2, an ESCA scan was performed on a sampleof the resulting media #3. FIG. 14 shows an ESCA scan 1400 of a sampleof media #3. The ESCA scan indicates that at least one sulfur species ispresent, as shown by peaks 1405. The composition of a sample of media #3includes approximately 69.5% oxygen, 28.2% aluminum, 0.2% sulfur, and2.1% carbon. The sulfur exists as about 50% sulfate species and 50%sulfide species. The capacity of a sample of media #3, as determined bya spin test, was determined to be about 763 mg-mercury/kg-media.

As stated generally herein, the parameters in Table 2 can be varied toachieve desired media. For example, during the reaction step (150), thehydrogen sulfide concentration can be varied from 2-5 vol %, thehydrogen concentration can be varied from 3-10 vol %, the nitrogenconcentration can be varied from 50-95 vol %, and the air concentrationcan be varied from 0-35 vol %. Furthermore, the reaction temperature canbe varied from 120-400° C., and the reaction time can be varied from 1-5hours.

Illustrative Example Media #4

An active media, media #4, was prepared according to the methoddescribed in Table 2. However, a SULFATREAT XLP material (available fromM-I SWACO of Houston, Tex.), with sizing capability in US mesh sizes of12 to 100, was used as the media base in place of the Maxcel 740material. All other steps in the process remained essentially the sameas used to produce media #3.

FIG. 15 shows an ESCA scan 1500 of a sample of virgin SULFATREAT XLPmaterial (untreated and unused). As shown in FIG. 15, there is verylittle sulfur in this virgin catalyst, which would appear in areas 1505of the ESCA scan. The composition of the virgin material includesapproximately 50% oxygen, 0.3% aluminum, 0.1% sulfur, 10.6% iron, 35.1%carbon, and 3.8% silicon. The sulfur species exists as nearly 100%sulfate.

After the virgin material was treated according to method 100 using theparameters set forth in Table 2, an ESCA scan was performed on a sampleof the resulting media #4. FIG. 16 shows an ESCA scan 1600 of a sampleof media #4. The ESCA scan indicates that sulfur species are present, asshown by peaks 1605. The composition of a sample of media #4 includesapproximately 49.6% oxygen, 0.4% aluminum, 3.4% sulfur, 13.7% iron,28.5% carbon, and 4.4% silicon. The sulfur exists as about 30% sulfatespecies and about 70% sulfide species. The capacity of samples of media#4, as determined by a spin test, ranged from about 1011mg-mercury/kg-media to 1127 mg-mercury/kg-media. Meanwhile, the capacityof samples of media #4, as determined by a column test, ranged from atleast 2759 mg-mercury/kg-media to at least 3822 mg-mercury/kg-media. Thecapacity of another sample of media #4, as determined by a column testof extended duration, was at least 12,238 mg-mercury/kg-media (for anequivalent effective treatment life of over 27,434 bed volumes).

FIG. 17 shows an ESCA scan 1700 of a sample of media #4 after it hasbeen washed with water. The ESCA scan shows that the sulfur species werestill present after washing (peak 1705), thereby suggesting the sulfurspecies is bound or linked to the support substrate in some way. Thecomposition of a sample of media #4 after washing includes approximately51% oxygen, 0.5% aluminum, 1.7% sulfur, 10.9% iron, 28.5% carbon, 6.4%silicon, and 0.9% Ca. The sulfur exists as about 20% sulfate species and80% sulfide species. The capacity of a sample of this media #4 afterwashing, as determined by a spin test, was about 445mg-mercury/kg-media.

Illustrative Example Media #5

An active media, media #5, was prepared according to the methoddescribed in Table 2. However, a spent SULFATREAT XLP material, whichhad been used to remove hydrogen sulfide from natural gas, was used asthe media base in place of the Maxcel 740 material. All other steps inthe process remained essentially the same as used to produce media #3.

FIG. 18 shows an ESCA scan 1800 of a sample of spent SULFATREAT XLPmaterial (untreated and used). As shown in FIG. 18, several sulfurspecies exist in the spent material, as shown by peaks 1805(corresponding to sulfide), 1810 (corresponding to sulfite), and 1815(corresponding to sulfate). The composition of the spent materialincludes approximately 49.6% oxygen, 0.8% aluminum, 5.3% sulfur, 8.7%iron, 29.3% carbon, 4.6% silicon, and 1.7% chlorine. The sulfur speciesexists as nearly equal portions of sulfate and sulfide, with traceamount of sulfite. The capacity of samples of this media #5, asdetermined by a spin test, ranged from about 332 mg-mercury/kg-media toabout 1025 mg-mercury/kg-media.

After the spent SULFATREAT XLP material was treated according to method100 using the parameters set forth in Table 2, an ESCA scan wasperformed on a sample of the resulting media #5. FIG. 19 shows an ESCAscan 1900 of a sample of media #5. The ESCA scan indicates that sulfurspecies are present, as shown by peaks 1905. The amount of sulfurspecies present increased relative to the used SULFATREAT XLP alone. Thecomposition of a sample of media #5 includes approximately 50.4% oxygen,1.2% aluminum, 7.3% sulfur, 9.3% iron, 25.8% carbon, 3.2% silicon, 1.3%chlorine, 0.8% calcium, and 0.7% sodium. The sulfur exists as about 60%sulfate species and about 40% sulfide species. The capacity of a sampleof media #5, as determined by a spin test, was about 1924mg-mercury/kg-media.

Illustrative Example Media #6

An active media, media #6, was prepared according to the methoddescribed in Table 3. The representative steps of method 100 are alsolisted in Table 3.

TABLE 3 Illustrative parameters for manufacture of media #6 Media base(step 110) Maxcel 740 virgin alumina Claus catalyst; target Net LOI at1000° C. <7%; macro porosity at 750 Å of greater than 0.1 cc/g Mediasizing (step Media is ground to sizing of 12 × 40 mesh prior 160) tofurther processing Mixing (step 130) Sulfur powder (−100 US mesh and99.9% pure) is added and physically mixed with the alumina substrate;concentration can range from 15-35 wt % Drying (step 140) The mixture isheated to 120° C. for 30 minutes Reaction temperature, The mixture ofsubstrate and sulfur is reacted atmospheric composition, and with H₂S(less than 5 vol %), H₂ (20 vol %), the reaction duration (step 150)balance N₂ for up to 90 minutes at 250° C. at pressures up to 10 psigCooling (step 150) Media is cooled in the presence of H₂S, H₂, and N₂ atreaction ratios until the media is 70° C.

After the virgin Maxcel 740 catalyst was treated according to method 100using the parameters set forth in Table 3, an ESCA scan was performed ona sample of the resulting media #6.

FIG. 20 shows an ESCA scan 2000 of a sample of media #6. The ESCA scanindicates that sulfur species are present, as shown by peaks 2005. Thecomposition of a sample of media #6 includes approximately 58.7% oxygen,24.2% aluminum, 3.2% sulfur, 13.6% carbon, and 0.2% sodium. The sulfurexists as about 20% sulfate species and about 80% sulfide species. Thecapacity of samples of media #6, as determined by a spin test, rangedfrom about 1021 mg-mercury/kg-media to about 1630 mg-mercury/kg-media.Meanwhile, the capacity of a sample of media #6, as determined by acolumn test, was at least 3681 mg-mercury/kg-media. The capacity ofanother sample of media #6, as determined by a column test of extendedduration, was at least 10,332 mg-mercury/kg-media (for an equivalenteffective treatment life of over 18,160 bed volumes).

As stated generally herein, the parameters in Table 3 can be varied toachieve desired media. For example, during the reaction step (150), thehydrogen sulfide concentration can be varied from 2-5 vol %, thehydrogen concentration can be varied from 3-10 vol %, and the nitrogenconcentration can be varied from 85-95 vol %. Furthermore, the reactiontemperature can vary from 130-300° C., and the reaction time can varyfrom 0.5-2.0 hours. The amount of sulfur mixed with the substrate canvary between 10-35 wt % of the combined weight of the substrate andsulfur.

A water sample was treated with media #5 to reduce metal ion impuritylevels. The concentrations of metals were analyzed. The results areshown in Table 4. As Table 4 shows, most metal ions, including mercury,arsenic, cadmium, were effectively removed and the residue barium andchromium levels were below the TCLP (Toxic Characteristic LeachingProcedure) limits.

TABLE 4 Treatment of water sample by media #5 Metal Ion Measureconcentration Unit Arsenic Non Detected mg/L Barium 0.0575 mg/L CadmiumNon Detected mg/L Chromium 0.0660 mg/L Lead Non Detected mg/L SeleniumNon Detected mg/L Silver Non Detected mg/L Mercury Non Detected mg/L

As described throughout the disclosure, the methods, systems, andtechniques presented herein overcome the limitations and drawbacks ofthe known techniques. It will be appreciated that the scope of thepresent invention is not limited to the above-described embodiments, butencompasses modifications of and improvements to what has beendescribed.

What is claimed is:
 1. A method of reducing a level of metallic species contamination of a fluid, the method comprising: contacting the fluid including the metallic species contamination with a sorption media, wherein the sorption media comprises a sulfur species chemically bonded to a support substrate, wherein the support substrate comprises an iron species.
 2. The method of claim 1, wherein the sulfur species is chemically bonded to the support substrate by at least one of an ionic bond and a covalent bond.
 3. The method of claim 1, wherein the support substrate includes at least one of an iron-, alumina-, silicon-, titanium, and carbon-based substrate.
 4. The method of claim 1, the support substrate further comprising a copper species.
 5. The method of claim 1, wherein the support substrate comprises alumina.
 6. The method of claim 1, wherein the sulfur species comprises at least one of a sulfate, a sulfite, and a sulfide species.
 7. The method of claim 1, wherein the fluid comprises an aqueous liquid.
 8. The method of claim 1, wherein the metallic species contamination comprises at least one of arsenic, mercury, a D-block metal, and a heavy metal species.
 9. The method of claim 1, wherein the metallic species contamination comprises at least one of selenium, nickel, barium, strontium, uranium, lead, titanium, zinc, and chromium species.
 10. The method of claim 1, wherein the metallic species contamination comprises at least one ionic mercury species, the method further comprising selecting the sorption media for contacting the fluid from a plurality of sorption medias based on the sulfur species of the selected sorption media including a sulfide species.
 11. A method of reducing a level of metallic species contamination of a fluid, the method comprising: selecting a sorption media comprising a sulfate species chemically bonded to a support substrate for contacting the fluid from a plurality of sorption medias based on the metallic species contamination comprising at least one inorganic mercury species; and contacting the fluid including the metallic species contamination with the selected sorption media.
 12. A method of reducing a level of metallic species contamination of a fluid, the method comprising: selecting a sorption media comprising a sulfate species and a sulfide species chemically bonded to a support substrate for contacting the fluid from a plurality of sorption medias based on the metallic species contamination comprising at least one inorganic mercury species and at least one ionic mercury species; and contacting the fluid including the metallic species contamination with the selected sorption media.
 13. A method of reducing a level of metallic species contamination of a fluid, the method comprising: selecting at least a first sorption media including a sulfate species chemically bonded to a first support substrate and a second sorption media including a sulfide species chemically bonded to a second support substrate for contacting the fluid from a plurality of sorption medias based on the metallic species contamination comprising at least one inorganic mercury species and at least one ionic mercury species; and contacting the fluid including the metallic species contamination with the selected sorption medias.
 14. The method of claim 1, wherein at least a portion of the sorption media is entrained in a filter material.
 15. A method of reducing a level of metallic species contamination of a fluid, the method comprising: contacting the fluid including the metallic species contamination with a sorption media, wherein the sorption media comprises a sulfur species chemically bonded to a support substrate and wherein at least a portion of the sorption media is incorporated into a clay liner material. 